The present invention relates to generally a matrix type flat discharge display pannel for displaying alpha-numerics, figures or images by utilizing DC gas discharges, and more particularly, a flat discharge display panel of the type described above and further having a memory function.
Various types of discharge display units utilizing DC gas discharges have been invented and demonstrated, and they are generally divided into two types, one utilizing negative glow and the other utilizing the positive column. Each discharge display unit is capable of producing a main discharge which is used for display purposes and an auxiliary discharge which facilitates the initiation of the main discharge. However, in the conventional discharge display units either or both of the main and auxiliary discharges are produced in the vertical direction relative to the transparent, insulating face plate of the discharge display panel so that an insulating plate having a large number of small holes which define the discharge spaces must be provided. This insulating plate must have a thickness sufficient for producing the negative glow or positive column. However, forming a large number of such small holes in a thick insulating plate presents a very serious problem when it is desired to enlarge the display area or to increase the number of discharge display units per unit area of a discharge display panel.
When a display in color is desired, a suitable phosphor is coated over the inner wall surfaces of the small holes, but since the small holes or discharge spaces are vertical to the face plate, only a small portion of light emitted can be used for display purposes. Thus, the conventional discharge display units have a common defect in that their luminosity, as well as light emitting efficiency, are very low.
There has been also devised and demonstrated a DC gas discharge display unit of the type wherein the plasma discharge constituting the main discharge is produced in parallel with the face plate. This discharge display unit has an advantage in that the small holes which are used as the main discharge spaces may be eliminated. Another advantage is its capability of producing highly luminous light. However, the auxiliary discharge is produced vertical to the face plate so that there still remains the problem of forming a large number of small holes vertical to the face plate which are used as the auxiliary discharge spaces. In addition, in this unit the cathode is interposed between the main and auxiliary anodes so that it is extremely difficult to add a memory function to the discharge units which are arrayed in matrix form.